The popularity of smartphones, tablets, and many types of information appliances is driving demand and acceptance of touchscreens for portable and functional electronics. Touchscreens are found, among other places, in the medical field and in heavy industry, as well as for automated teller machines (ATMs), and kiosks such as museum displays or room automation, where keyboard and mouse systems do not allow a suitably intuitive, rapid, or accurate interaction by the user with the display's content.
Touchscreen displays continue to increase in size. Large touchscreens (e.g., greater than eighty inch diagonal) are being used as lecture tools in front of audiences, for example. Touchscreens allow a user to manipulate objects displayed by the touchscreen, such as object selection, positioning (e.g., dragging), and so on. Although touchscreens allow users to interact with displayed data, some existing systems have a number of drawbacks. For instance, when large touchscreens are used, some systems cannot properly interpret an input if multiple touch commands are received. Unlike a small screen, where a user may only utilize one hand or one finger, the interpretation of inputs from multiple or simultaneous touch commands on a large touchscreen may cause an error or inadvertent input.